The first episode of the series introduces Nanoha and shows how her powers were first awakened.

Nanoha Takamachi: Under this great big sky, there are thousands, no, tens of thousands of people. All kinds of people with all sorts of wishes and feelings hiding inside. Sometimes, a person's emotions can touch and clash with someone else's. And there's people whose feelings can bond with another so perfectly, they can talk without saying a word. Well, this is a story about people like that, and what happens when they eventually meet. Magical Girl Lyrical Nanoha is about to start!

Nanoha: I am the one who has been given a mission. Under the contract, release those powers unto me. Winds to the sky, stars to the heavens, and the unyielding soul to this heart! Magic to these hands! Raising Heart, set up!

A Jewel Seed causes a city-wide catastrophe in Nanoha's home of Uminari City.

Raising Heart: Area search.

Nanoha Takamachi: Lyrical, magical! Search for the root of this terrible misfortune!

Nanoha: Now I can seal it away!

Yuuno Scrya: It's impossible from here, you have to get closer!

Nanoha: It's all right, I can do it! We can do it, can't we, Raising Heart?

Raising Heart: Shooting Mode. Set up.

Nanoha: (voiceover) That was my first mistake since becoming a mage. It doesn't feel too good when you realize that you're the reason for someone else's suffering. And when I decided to help Yuuno, I knew that, or I thought I did... From now on, I'll do better than my best. I'll give it everything I've got. This isn't just for Yuuno anymore, this is my decision, my choice. I'll collect every last one of those Jewel Seeds. I'll make sure that something like this never happens again.

Nanoha's friends start to notice her preoccupation with Fate and with her activities as a magical girl.

Arisa Bannings: It just irritates me! It's obvious that she's worried about something. And it's obvious that she's trying to decide on something and that she's in trouble! But no matter how much we ask her, or offer to help with it, she won't tell us anything. She's lying straight to our faces about everything!

Suzuka Tsukimura: No matter how good a friend we are, there are some things that we just can't tell each other.

Amidst Fate and Nanoha's continuing fight for the Jewel Seeds, a third group arrives.

Nanoha Takamachi: Wait a minute... All I want to do is talk to you for a bit, Fate. I have an idea though. I'm not some spoiled kid, so if you wanna fight, let's fight. But if I win... Will you talk to me?

Nanoha meets with the Time-Space Administration Bureau and learns the full details of the situation.

Lindy Harlaown: On rare occasions, worlds are born that evolve too much, too quickly. When the pressure of that evolution becomes too great, they tend to destroy themselves through technology and science.

Nanoha: (silently) Someone to share my feelings... Someone with whom I can split the loneliness and sadness in half... That's it. Now I understand what I want. I want to share my feelings with this girl. (out loud to Fate) All I want... is to be friends.

Chrono Harlaown: Even under the circumstances, she can’t deny that she was an accomplice in the dimensional interference. It’s because this is a felony. Normally, the punishment for this would be imprisonment for a couple hundred years…

Nanoha Takamachi: No way!

Chrono Harlaown: However! The situation is unique this time, and it’s clear that she didn’t willingly participate in the crime. All that’s really left is getting the higher-ups to understand. But I’m confident in my ability to do that, so don’t worry. The Time-Space Administration Bureau isn’t so cold as to question a girl who unknowingly committed a sin when she was simply trying to fulfill her mother’s wish

The newly awakened Book of Darkness mercilessly attacks Nanoha and Fate while Chrono reveals the mastermind behind the entire incident.

Aria Lieze: Chrono, look, it's not too late just yet! Set us free while we still have time. The only time we can freeze the Book of Darkness is within a few minutes after it goes out of control!

Chrono Harlaown: But until that point is reached, the owner of the Book is not yet considered some criminal who needs to be sealed away forever. That would be illegal.

Lotte Lieze: And because of that...! Because of that law, that tragedy has been repeated over and over again! That's why Clyde was... That's why your own father had to go away and-

Graham: That's enough.

Chrono: The law aside, there is a problem with your plan. First of all, the removal of the freeze would not be that hard. No matter where you hide it or how well you protect it, someone will try to find it, and try to use it. Anger and sadness, greed and desire, those are the kinds of wishes that can lead one to the sealed power.

What was supposed to be a simple training battle causes chaos amidst the members of the Sixth Mobile Division.

Nanoha Takamachi: I wasn’t at the scene but Vice-captain Vita has already scolded you. So I think you’ve already reflected on your mistake. I won’t scold you a second time. But Teana, I think you try too hard every now and then. It’s becoming a bit of a problem. You have to remember that you aren’t fighting alone. Our position in combat has us surrounded by allies. That’s why you made your mistake today. Think about it carefully and make sure it doesn’t happen again.

Nanoha Takamachi: It’s strange. You two, what happened to you? I know you’re trying your best, but a mock battle isn’t a brawl. If you’re just pretending to listen during practice and then being this dangerous during the real thing, then training has no meaning, does it? Let’s do it properly, like we do in practice. My training… is it really that wrong?

Tiana Lanster: (crying, screaming) I just don't want anyone to get hurt anymore! I don't want to lose anything anymore! That's why I want to get stronger!

After the chaotic mock battle of the previous day, the forwards learn why Nanoha has been training them with restraint.

Signum: (To Teana) There are battles that must not be lost even if it means being reckless or risking your life. However, that time you missed your shot, was it a situation where you had to shoot even if you risked the safety or life of your comrade? Using a move like that in training, just whose sake was that for? What was it for?

Shario Finenio: Nanoha-san doesn’t want any of you to go through what she did. So that you don’t have to push yourself and to be absolutely, positively sure that you come back safe and sound, she has been training you with care, thinking about your safety the entire time.

The Forwards go out with the captains while they discuss dealing with the prophecy and the potential threat of Lieutenant General Regius's proposed inspection.

Verossa Acous: (on Hayate) Rare skills, powerful magic, strong power and the authority to have other people serve her; having that power implies a degree of isolation. That’s what I think. Of course, she’ll be needed. She’ll be relied on. But not as a person, it’ll be the power she possesses being relied on. (pause) Of course, that’s an extreme case. It’s not actually like that.

Teana Lanster: Yes, I see. “Pressure and loneliness come with power.”

Verossa Acous: Anyway, what I’m trying to say is, well, I’m sure that a lot of things will happen between the commander and the front line members, but I’d like you to treat her not just as a superior, but as a person, another girl. Not just Hayate but the captains, too.

Teana Lanster: (salutes) Roger. The frontline members will do the best they can.

Scaglietti's forces gain the upper hand over the forces of Section Six, and the battle starts to look hopeless.

Quattro: (thinks to herself) A weak life that can’t do anything is no different than an insect’s. No matter how many you kill, more will keep being born. Playing with them and abusing them, throwing them into a cage and watchng them suffer, it’s so much fun! Right?

Lutecia Alpine: Zest will be gone soon. Agito will go somewhere too, I’m sure. But when this festival is over, Doctor, Uno and the others will look for XI for me. Then my mom will come back. Then I won’t be unhappy anymore.

Caro Ru Lusie: That’s not true!

Lutecia Alpine : I don’t like talking to you.

Caro Ru Lusie: If you want to be happy, then no matter how unhappy you are, you can’t make others unhappy or hurt them! If you do that, you won’t find what you want, especially happiness!

The battles of the Stars team, Subaru and Tia, begin to turn in their favor as Nanoha finally reaches the kidnapped Vivio, only to be attacked by her.

Mach Caliber: You taught me the reason for my being here, my strength and power which you adore so much. Don’t make everything a lie.

Subaru Nakajima: (in a flashback) When a war or a disaster or something bad happens, I want to be able to save people who are sad, in pain, and shouting “Save me!” To take them straight to somewhere safe by my own power. (thinking in the present) To be honest, I’m always scared and uneasy about fighting, about hurting someone, my hands still shake. But this power in my hands isn’t to destroy, it’s to protect. The power to break through a sad reality.

Caro Ru Lusie: If she's in doubt, then we will be right there by her side. If she's in trouble, we'll be right there to save her.

Erio: If she, for some reason, is wrong, we'll be there to scold her and then return back to her. We, all of us are here for her.

Caro: So, don't lose. Don't hesitate.

Together: Fight!

Fate Testarossa: Sorry, and thank you, Erio, Caro. There’s nothing to doubt, right? Because I was weak, I was hesitating and worrying. I will probably always repeat this. That’s fine. Because all of that makes me.

Teana Lanster: I don’t know what you’ve been through, but if you recognize your crimes and seek asylum, I think you’ll be allowed a fresh start.

Nove: There’s no way that’ll happen. We’re combat cyborgs. There’s no way of life to us other than just fighting and winning! (Deed tries to get up but Vice hits her in the head with a perfectly aimed sniper bullet, knocking her out. Teana advances on Nove and holds her dagger to her throat)

Teana: Even weapons that exist only for fighting can laugh and live kindly. (Cut to Subaru holding Ginga in her arms) You may have been born a combat cyborg, but I know a girl who’s more human than anyone, who’s stupidly kind and tries her best.

Quattro: (hearing of her sisters’ defeat) They’re all complete losers. Well, it’ll all work out if I’m around? Right, Doctor?

Quattro: Area search? No way! She's been looking for me this whole time? But this is the deepest part of the Cradle. Nobody could make it all the way down here... (glances at readout, eyes widen) She's going to just blast through the walls? Oh Dear Mother of God!

Raising Heart: Clearance confirmation. Firing lock is cancelled.

Nanoha: Blaster Three! Divine... Buster!

Vivio: All my sadness, my pain, they were fake, created things. I can't be allowed to live!

Nanoha Takamachi: You're wrong. No matter how you were born, the Vivio that's there crying is not a fake or something that was merely created. She's the spoiled girl who cries all the time and can't even get up on her own when she trips. The girl who hates her green peppers, the girl who pats me on the head when I'm lonely... My beloved Vivio. I'm not your real mama, but I'm going to try my best to be. So don't say that you can't be allowed to live. Tell me your true feelings.

Vivio: I... Nanoha-mama... I love you! I want to be with you forever! Mama... Save me!